Video 10:53
Pea Struck

As landholders living near Warrumbungle National Park in New South Wales began to recover from two natural disasters, they faced a triple-whammy when an unexpected pest began killing livestock.

Transcript

PIP COURTNEY, PRESENTER: Fire and drought are two of the worst natural disasters farmers can face. But landholders living near the Warrumbungle National Park, in the central west of New South Wales, this year faced a triple whammy. Out of the ashes arose an unexpected pest with a poisonous secret.

Joanna Woodburn reports.

JOANNA WOODBURN, REPORTER: The scars are still plain to see on the gnarled Warrumbungle Range, the hills unable to hide the effect of last January's catastrophe.

STEPHEN LILL, FARMER: An enormous fireball came out of the sky and just landed half a kilometre away from here and just exploded. This was not a fire, this was a firestorm.

JOANNA WOODBURN: What started as a bushfire in the Warrumbungle National Park in central western New South Wales quickly became an inferno. With temperatures hovering in the mid-40s and strong, gusty winds whipping up the flames, the fire front became a wall of fire, stretching 20 kilometres and bearing down on farms.

PETER SHINTON, WARRAMBUNGLE SHIRE MAYOR: It was absolutely disastrous. I can remember in the afternoon when I got a phone call to come into the bushfire control centre and all I could see was a wisp of smoke and I thought, 'I wonder what this is all about.'

Then they informed me that there would be wind changes, extreme wind changes in the afternoon and that it would reach the catastrophic class of fire. And I stayed there for I think about two hours and when I left the building, then we could see it. It was quite massive and you could tell all hell was breaking loose underneath the fire.

JOANNA WOODBURN: During the next two weeks, the fire burnt through 53,000 hectares of national park and farms. Around 150 houses and outbuildings were destroyed. More than 1,000 head of livestock perished.

The fire burnt everything in its path. Many of these trees will never regenerate. The only thing that has taken hold, choking out everything else, is Darling Pea, a thick impervious mat which can be fatal to livestock.

Darling Pea, or Swainsona, is common throughout Australia.* But it was the devastating chain of events of bushfire, flash flooding and drought that gave it unprecedented conditions to thrive.

JOHN UNWIN, WEEDS INSPECTOR: The Darling Pea, being a native, is used to fire and most Australian natives are quite used to fire. There's no competition and on top of a rather large bushfire we got a drought.

TONY KNIGHT, FARMER: That was the worst of the lot. We had the fire that came through, then we had a flash flood that destroyed a lot of the fences down around the creeks and things. That was bad enough. But then, yes, we thought we'd suffered enough, but to get a very dry spring and summer, you know... there was a lot of stress about there for a while.

JOANNA WOODBURN: Tony Knight farms at Berimbuckle, south-west of Coonabarabran. His family has been on this land since 1852. He lost more than 200 sheep, kilometres of fencing and hundreds of hectares of pastures in the bushfire. Within weeks, the drought and Darling Pea tightened their grip.

TONY KNIGHT: Next thing it's, you know, a metre high and all over the place and it's starting to get very toxic.

JOANNA WOODBURN: So far the pea has killed 800 of the Knights' sheep and they expect the death toll to rise further.

TONY KNIGHT: The time that the sheep were getting poisoned, we had a lot of things on our mind. We'd had the effects of the fire, trying to get everything back to normal and the pea was a real problem when it was starting to get dry. And it just became one of our problems. It would have been nice if we could have spent more time with them, if we could have mustered them more, taken the affected ones out and put them on a paddock that had no pea.

JOANNA WOODBURN: The seemingly innocuous-looking Darling Pea holds a poisonous secret. The toxins affect an animal's brain by attacking an enzyme involved in metabolism. Local vets performed autopsies on some of the Knights' stock which had suspected Darling Pea poisoning.

GREG MCCANN, REGIONAL VETERINARIAN: There are certain changes in the cells that are pretty, that are indicative of Swainsona poisoning. And these changes were present in the samples that were submitted and hence we got a positive diagnosis as to yes, what killed these particular sheep was Swainsona or Darling Pea.

JOANNA WOODBURN: The pea is also highly addictive and can condemn its victims to a slow death.

GREG MCCANN: They lose the ability to judge where their feet are, so they become wonky or ataxic, falling over and they also can appear to be blind, walking into things. They can assume funny postures, like head bent down or head bent right back. But the one thing that was seen in the cases associated with the Coonabarabran area were muscle twitching and the people that tried to muster the stock that were affected found them very difficult to muster because they wouldn't act like they normally would.

JOANNA WOODBURN: In this mob of Tony Knight's, a few sheep appear to be suffering from pea-mania; behaving differently from the others. And the incident isn't isolated to his farm.

JOHN UNWIN: A lot of landholders lost a lot of stock. And unfortunately in my position I had phone calls from wives and basically because it's a native plant, all I could offer was sympathy.

This particular lady was devastated. I mean, she'd just gone through the worst fire that I'd ever seen in my life and she'd lost stock in that. They'd lost infrastructure all over their land and now we've got a plant that is there normally in an odd plant here and there as a sheet, destroying the stock and sending them crazy.

So you can imagine, from the emotions from the fire and then having what was left of their animals going crazy on stuff that they were eating, it certainly shook them up.

JOANNA WOODBURN: Back towards Coonabarabran is Chadwick Downs, which was one of the properties that bore the brunt of stock losses in the bushfire.

A tinge of green is starting to return to the landscape, but at the height of the fire, Stephen Lill's Braford and Brangus stud lost around 200 cows and calves, many of them valuable breeding stock. Parts of his property have also become overrun by Darling Pea.

STEPHEN LILL, FARMER: The weeds that came after the fire were quite different pattern. Usually weed infestation happens gradually and you have options to adopt, whether it's moving cattle or sheep off that area and letting the weeds go through their poisonous stage and then reintroducing them. But this year we didn't have the options because of the fire and no feed.

JOANNA WOODBURN: Fifteen varieties of Darling Pea are found in New South Wales. Five are listed as vulnerable or endangered. Because they're native, a landholder may need government approval for any control programs and these are determined on a case by case basis. The most effective treatment is rotating livestock.

GREG MCCANN: As long as you can move the animals, as long as you can move the stock, you can actually graze the pea for a period and the advice has been to graze it for a period of four weeks and then remove them. Now, the toxin really doesn't start to cause problems until after the animals have been grazing for over two months, so they can actually make use of the greenery for a four-week period and take them off without any ill effects.

JOANNA WOODBURN: Tony Knight didn't have this luxury.

TONY KNIGHT: Just made it so hard. We just had to get, pretty much drop everything and get these fences up to have any sort of control over them at all.

JOANNA WOODBURN: Even if they'd sought approval to spray, it wasn't economical or practical.

TONY KNIGHT: No, it was just too difficult. You would need a helicopter to spray it and even then you'd be spraying an awful lot of foliage. There was so much under the timbered country, you couldn't effectively spray it in amongst the trees.

JOANNA WOODBURN: The fire started a few kilometres to the west of here. The damage it's caused and the knock-on effects are still being felt by the farming community and it's generated significant concern. An inquest and New South Wales parliamentary inquiry are due to be held to look at what sparked the blaze and how it was managed.

STEPHEN LILL: Nature deals a strange set of cards at times, and you learn to work with the cards that you've been dealt.

JOANNA WOODBURN: A succession of bad luck has stripped many farmers of their ability to easily navigate the next challenge.

TONY KNIGHT: More suitable pasture would certainly help. More pasture on the land that doesn't have the pea, so that we can take the sheep down and get them off it there for a while. We can get the ones, the affected ones, keep them away from it. That's about the only thing that we can do.

JOANNA WOODBURN: The soaking rain that's now drenched parts of the Coonabarabran district could be the break Tony Knight and Stephen Lill have been waiting for.

TONY KNIGHT: I really think that we're due for a good season around here. We haven't had a good season for a long time and fingers crossed is that this year will be good. We've certainly had a very good start and as long as we can get a little bit more rain in the autumn we should go into the best winter we've had for a long time.

JOANNA WOODBURN: While they could never have predicted what's transpired during the past year, they're hopeful a brighter season lies ahead.

TONY KNIGHT: You wouldn't dream it would ever happen like that. Oh, yes, we just feel that we've had our share of bad luck. The luck's got to change.

*Editor's note: Darling Pea refers to a number of species mainly found in New South Wales and Victoria. It belongs to the Swainsona genus of plants, which can be found throughout mainland Australia.